(a) Field of the Invention
The present invention relates to a liquid crystal display (“LCD”) and method thereof. More particularly, the present invention relates to an LCD minimizing occurrence of vertical cross-talk and a method of minimizing vertical cross-talk in the LCD.
(b) Description of the Related Art
Liquid crystal displays (“LCDs”) are one of the most widely used flat panel displays. An LCD includes a pair of panels including field-generating electrodes such as pixel electrodes and a common electrode, and a liquid crystal (“LC”) layer interposed between the panels. The LCD generates an electric field in the LC layer by applying voltages to the electrodes, and obtains desired images by controlling the strength of the electric field for determining orientations of LC molecules within the LC layer and polarization of light incident on the LC layer to vary the transmittance of light incident on the LC layer.
An LCD also includes switching elements connected to the respective pixel electrodes, and a plurality of signal lines such as gate lines and data lines for controlling the switching elements and thereby applying voltages to the pixel electrodes.
A vertically aligned (“VA”) mode LCD, which aligns the major axes of the LC molecules perpendicular to the upper and lower panels in the absence of an electric field, has a high contrast ratio and wide reference viewing angle. The reference viewing angle is defined as a viewing angle making the contrast ratio equal to 1:10 or as a limit angle for the inversion in luminance between the grays.
To implement a wide viewing angle in the VA mode LCD, cutouts are provided in the field generating electrodes or protrusions are provided on the field generating electrodes. Since the cutouts and the protrusions can determine the tilt directions of the LC molecules, the tilt directions can be distributed into several directions by using cutouts and protrusions, thereby imparting a wide reference viewing angle.
In the case of a patterned vertically aligned (“PVA”) mode LCD, in order to improve the lateral visibility, it has been suggested to divide each of the pixel electrodes into two sub-pixel electrodes that are capacitively coupled to each other. Then, one sub-pixel is applied with a voltage directly and the other sub-pixel is supplied with a lower voltage due to the capacitive coupling so that the two sub-pixel electrodes have different voltages from each other, which causes different transmittances of the two sub-pixels.
Voltages are applied to the field-generating electrodes in the LCD to generate an electric field in the LC layer and the strength of the electric field is regulated to adjust transmittance of light passing through the LC layer, thereby displaying desired images. To prevent the LC layer from deterioration due to a one-directional electric field applied for a long time, the polarity of a data voltage is reversed for each frame, for each row, or for each pixel with respect to a common voltage.